RU2596730C2 - Method of producing reduced iron agglomerates - Google Patents

Abstract

FIELD: metallurgy; technological processes.

SUBSTANCE: invention relates to a method of producing reduced iron agglomerates. Compacts containing iron oxide material and carbonaceous reducing agent are loaded on heating furnace floor with a moving bed and heated to reduce iron oxide in compacts. At that, use is made of compacts, every of which contains iron oxide material, an average particle diameter of which varies from 4 to 23 micron, and contains particles, the diameter of which is equal to 10 microns or less in the amount of 18 mass percents or more.

EFFECT: invention provides higher output of reduced iron agglomerates, particles of which have larger diameters, shorter duration of production, which increases efficiency, and considerable reduction of content of impurities, such as sulphur, in reduced iron agglomerates.

6 cl, 11 tbl

Description

FIELD OF THE INVENTION

The present invention relates to a method for producing reduced iron agglomerates by loading compacts consisting of a mixture of raw materials, which comprises an iron oxide material and a carbon reducing agent, under a movable bed heating furnace and heating the compacts in order to subject the iron oxide in the compacts to reduction or smelting reduction.

BACKGROUND OF THE INVENTION

A direct reduction method for producing iron has been developed to produce agglomerated (including granular) metallic iron (reduced iron) from a mixture containing an iron oxide source (hereinafter also referred to as “iron oxide material”), for example iron ore or iron oxide, and containing carbon reducing agent (hereinafter also referred to as "carbon reducing agent"). When implementing such a method of manufacturing iron, compacts, in the form of which the mixture is formed, are loaded onto a moving bed under a heating furnace. The compacts are heated in a furnace using gas heat exchange and radiant energy using a heating burner to reduce iron oxide in the compacts with a carbon reducing agent. After that, the obtained reduced iron is carburized, melted, and provides its coalescence in the form of agglomerates with simultaneous separation from the by-product slag. Then the agglomerates are cooled and solidified, obtaining agglomerated metallic iron (reduced iron agglomerates).

This method of making iron does not require the use of large-scale equipment, such as a blast furnace, and provides a high degree of flexibility in the use of resources, for example, eliminates the need for coke, therefore, recently such a process for producing iron has been studied to ensure practical application. However, its implementation on an industrial scale requires the solution of many problems related, for example, to a stable regime, safety, cost, quality of granular iron (cast iron) (i.e. product), productivity.

In particular, in order to obtain reduced iron agglomerates, it is desirable to improve the yield of coarse reduced iron agglomerates and recovery during the production period. With regard to this method, PTL 1 (patent source 1) states, for example, that “a method for producing granular metallic iron involves heating a raw material that includes an iron oxide material and a carbon reducing agent for reducing metal oxide in the raw material, followed by heating the resulting metal for the purpose of melting the metal and enabling coalescence of the metal to form granular metal during separation from the by-product slag component one in which the coalescence accelerating agent for by-product slag is contained in the raw material. "

According to this method, a high yield of coarse granular metal is achieved to some extent due to the use of a coalescence accelerating agent (e.g. fluorite). However, in addition, according to this method, the improvement effect is saturated, therefore, further improvement of such an effect is desirable.

Regarding the quality of the reduced iron agglomerates, the granular iron obtained by the described manufacturing method is fed into existing steelmaking equipment and used as an iron source. Thus, in granular iron (also called "granular cast iron"), a low content of impurity elements such as sulfur is provided. To achieve this, for example, in PTL2, it is stated that “a method for producing granular metallic iron having a low sulfur content comprises loading a mixture, which comprises an iron oxide-containing substance and a carbon reducing agent, under a movable bed heating furnace, heating the mixture to reduce the oxide iron in a mixture with a carbon reducing agent, ensuring the coalescence of the formed metallic iron in the form of granules during the separation of metallic iron from side slag and curing of the gran l as a result of cooling, the amount containing CaO, MgO and SiO ₂ materials in the mix is adjusted so that the basicity of the slag component, i.e. (CaO + MgO) / SiO ₂ is from 1.2 to 2.3 and that the MgO (MgO) content of the components contained in the slag is from 5% to 13%, determined based on the content of CaO, MgO and SiO ₂ in the mixture. "

According to this method, a MgO-containing substance (e.g. dolomite ore) is added to the mixture to control the slag components, thereby providing a low sulfur content in the granular metallic iron. According to this method, the improvement effect is also saturated, therefore, further improvement of such an effect is desirable.

It should be noted that coalescing accelerating agents, such as fluorite, and MgO-containing material, such as dolomite ore, are used as melting temperature control agents.

List of links

Patent Literature

PTL1: Publication of Unexamined Japanese Patent Application No. 2003-73722

PTL2: Publication of Unexamined Japanese Patent Application No. 2004-285399

Disclosure of invention

Technical challenge

The present invention was created in light of the above circumstances. The aim of the present invention is to develop a method for producing reduced iron agglomerates by heating compacts consisting of a mixture of raw materials, which includes at least iron oxide-containing material and a carbon reducing agent, in a moving bed heating device in order to subject iron oxide to reducing compacts smelting, while this method improves the yield of reduced iron agglomerates having a large grain size, increases production due to the reduction in production time and minimizes the content of impurity elements, such as sulfur, in reduced iron agglomerates.

The solution to the problem

A method for producing reduced iron agglomerates according to the present invention, which solves the problems described above, involves loading compacts, which include iron oxide material and a carbon reducing agent, under a movable bed heating furnace, and heating compacts to reduce iron oxide in compacts, in which compacts are used, each of which includes an iron oxide-containing material and has an average particle diameter of 4 to 23 microns, and contains particles whose diameter is 10 μm or less, in an amount of 18 wt.% or more.

In the method according to the present invention, a characteristic example of an iron oxide-containing material is iron ore. The average particle diameter of the iron oxide-containing material located in the central part of each of the compacts is preferably 4 to 23 microns.

Another method for producing reduced iron agglomerates according to the present invention, which solves the problems described above, involves loading compacts, which include an iron oxide-containing material, a carbon reducing agent and a melting temperature regulating agent, under a movable bed heating furnace, heating the compacts to reduce iron oxide in compacts, further heating of the compacts in order to at least partially melt the compacts, and coalescence of the iron component one in which compacts are used, each of which includes an iron oxide-containing material and has an average particle diameter of 4 to 23 μm, and contains particles whose diameter is 10 μm or less, in an amount of 18 wt.% or more.

In this method, a characteristic example of an iron oxide-containing material is iron ore. The average particle diameter of the iron oxide-containing material located in the central part of each of the compacts is preferably 4 to 23 microns.

Advantages of the Invention

According to the present invention, compacts consisting of a mixture of raw materials, which includes at least an iron oxide-containing material and a carbon reducing agent, are loaded on under a movable bed heating furnace and heated in order to subject the iron oxide in the reduction compacts, thereby providing obtaining reduced iron agglomerates. The average particle diameter and particle size distribution (particle size distribution) of the iron oxide-containing material is appropriately controlled, thereby improving the yield of reduced iron agglomerates having a large granule size, reducing production time, thereby increasing productivity, and minimizing the content of impurity elements such as sulfur , in reduced iron agglomerates.

Description of Embodiments

In the preparation of reduced iron agglomerates during the formation of compacts consisting of a mixture that includes an iron oxide material serving as a component such as a raw material, and a carbon reducing agent, as well as an iron oxide containing material, and a carbon reducing agent, respectively pulverized, and then adjusted so as to give them a uniform size in order to ensure their easy granulation. However, the influence of the size of such a component as a raw material (average particle diameter) on the yield and productivity with respect to reduced iron agglomerates was not taken into account. It was assumed that excessive grinding of such a component as a raw material leads to dispersion of this component, thereby preventing the coalescence of reduced iron and reducing productivity.

To achieve the above objectives, the authors of the present invention conducted research from the point of view of various perspectives. In particular, the inventors of the present invention studied the effect of particle diameter and particle size distribution of a component such as a raw material on productivity and found that the appropriate regulation of the average particle diameter and particle size distribution of the iron oxide-containing material contributes to the successful achievement of the described purpose. The findings made it possible to complete the present invention.

According to the present invention, it is necessary that the average particle diameter of the iron oxide-containing material in the agglomerates is 23 μm or less and contains particles whose diameter is 10 μm or less in an amount of 18 wt. % or more. As used herein, the term “average particle diameter” means a particle diameter (hereinafter also referred to as “D50”) corresponding to 50% of the mass of particles (cumulative value of 50% by weight) when counting the number of particles from the smallest particle. It is assumed that the reason for improving the yield of reduced iron agglomerates and productivity when using a component such as raw material is as follows.

The described compacts are subjected to reduction or reduction smelting at a temperature of from 1200 ° C to 1500 ° C. In the early stage of the reduction reaction, direct contact between the iron oxide-containing material and the carbonaceous reducing agent provides a further course of the reaction. Grinding the iron oxide-containing material to fine particles increases the likelihood of contact between the iron oxide-containing material and the carbon reducing agent, thereby shortening the reduction time. When the carbonaceous reducing agent begins to gasify, the reduction reaction proceeds from the surface of the iron oxide-containing material. Thus, grinding the iron oxide-containing material into small particles increases the surface area and reduces the recovery time and the time to produce reduced iron agglomerates (hereinafter, reduced iron agglomerates obtained by reduction smelting are also referred to in particular as “granular reduced iron”).

As a component of the raw material used in the present invention, a melting temperature controlling agent, for example, limestone, fluorite or dolomite ore, may be contained. In this case, grinding the iron oxide-containing material into fine particles reduces the distance between a component such as gangue in the iron oxide-containing material and the surface of the melting temperature-regulating agent (increases the likelihood that the gangue in the iron oxide-containing material is close to the surface of the regulating the melting point of the agent) and increases the frequency of contact between a component such as waste rock and the regulating melting temperature of the agent, thereby facilitating the formation of the molten product. This facilitates the separation of gangue from the iron oxide-containing material and the coalescence of such a reduced iron oxide component. In other words, a phenomenon can occur that is completely opposite to the phenomenon recognized in the past.

The sulfur component is mainly contained in the carbonaceous reducing agent. After gasification of the carbonaceous reducing agent, the sulfur component remains in the granules. The sulfur component is introduced into the granular reduced iron and gangue during smelting. According to the present invention, a component such as waste rock is easily formed. Thus, the sulfur component is more likely to smoothly and quickly transfer to the liquid component and is less likely to penetrate the granular reduced iron, thus, apparently, reducing the sulfur concentration in the granular reduced iron.

In order to ensure efficient production of such an action, the average particle diameter (D50) of the iron oxide-containing material should be 23 μm or less and contain particles whose diameter is 10 μm or less in an amount of 18 wt. % or more. The average particle diameter is preferably 17 μm or less. In the event that the average particle diameter (D50) is less than 4 μm, that is, it is too small, the formation of compacts is difficult.

As the iron oxide-containing material used in the present invention, iron ore, glandular sandstone, non-ferrous smelting waste or the like can be used. As the carbon reducing agent, carbon-containing material can be used. For example, coal or coke can be used.

Additional binder components, MgO source material, CaO source material and the like can be incorporated into the described compacts. Examples of a suitable binder include polysaccharides (e.g., starch, such as flour). Examples of suitable MgO source material include MgO powders, Mg-containing materials extracted from natural ore and seawater, and magnesium carbonate (MgCO ₃ ). Examples of a suitable CaO source material include calcined lime (CaO), slaked lime (Ca (OH) ₂ ) and limestone (main component: CaCO ₃ ). In addition, dolomite, which is a double salt of calcium carbonate and magnesium carbonate, can be used.

The shape of the compacts is not particularly limited. Her examples include pellets and briquettes. The size of the compacts is not particularly limited. The diameter (maximum diameter) is preferably 50 mm or less. In the event that the diameter of the compacts is too large, the agglomeration efficiency is reduced. Moreover, heat transfer to the lower parts of the pellets is reduced, thereby reducing productivity. The lower size limit is about 5 mm.

Not all particles of iron oxide-containing material in the compacts need to be pulverized to a powder state. Ten percent, based on the weight or more of the total iron oxide-containing material, can satisfy the average particle diameter requirement described above. An example of a structure that satisfies this requirement is a structure in which powdered iron oxide-containing material is present in at least only the central part of each of the compacts. When heating the compacts from the outside, the temperature increase in the central part of each compact slows down compared to the peripheral part. Thus, the reaction also slows down. To mitigate this phenomenon, it is effective to place the material containing iron oxide crushed into powder in the central part. The term “central part” means that, for example, if the compacts have a spherical shape (dry pellet, described below), the central part refers to a part extending from the center of the sphere to a point that satisfies the described average diameter of small particles (part outside the central part is called the "peripheral part").

In the event that the powdered iron oxide containing material is present in at least the central part of each of the compacts, the basic structure is as follows: the powdered iron oxide containing material described in the present invention is present only in the central part, and such a component as a raw material having a normal average particle diameter (not crushed) is present in the peripheral part. In addition, an embodiment of the present invention includes a structure in which all of the raw material used is an iron oxide-containing material that satisfies the average particle diameter and size distribution specified in the present invention.

This application claims the priority of Japanese Patent Application No. 2012-042395, filed February 28, 2012. Japanese Patent Application No. 2012-042395, filed February 28, 2012, is hereby incorporated by reference in its entirety.

EXAMPLES

Further, the present invention is described in detail with reference to examples, however, it is understood that the examples are not intended to limit the present invention. Any modifications within the scope of the above or below purpose are included in the technical scope of the present invention.

EXAMPLE 1

Compresses are obtained consisting of a mixture of a raw material comprising an iron oxide-containing material, a carbon reducing agent and a binder. The compacts are loaded into a heating furnace and heated in order to subject the iron oxide in the compacts to reduction smelting, resulting in reduced iron agglomerates (granular reduced iron).

In this case, iron ore A having the composition of the components (composition of the main components) described in Table 1 is used as the oxide-containing material. Coal having the composition of the components described in Table 2 is used as a carbon reducing agent. Pressings are obtained from components of a raw material (containing iron oxide material and a carbon reducing agent) having various average particle diameters and different particle size distributions. In particular, flour serving as a binder is mixed with iron ore and coal mixtures having different average particle diameters (D50) in the ratio described in Table 3. Cylindrical compacts are obtained, each of which has a diameter of 20 mm and a height of 10 mm (after molding, drying is carried out at 105 ° C for a whole day).

Table 1 Type of iron ore The composition of the components of iron ore (wt.%) General FeO SiO ₂ Cao Al ₂ O ₃ MgO S BUT 66.62 0.12 2.24 0,07 0.96 0,03 0.008 AT 67.61 29.14 4.9 0.45 0.23 0.49 0.003

table 2 The composition of the components of coal (wt.%) Bonded carbon Volatile component Ash Total 84.36 7.58 8.06 one hundred

Table 3 The ratio of the components of the mixture (wt.%) Iron ore Coal Binder Total 79.42 19.86 0.9 one hundred

The compacts are heated at 1300 ° C in a nitrogen atmosphere and the recovery rate (reaction time) is determined. The reaction time is defined as the time required for the reduction of iron oxide in iron ore to reach 90%. Table 4 describes the results obtained along with the used average particle diameters and particle size distributions of the raw materials (iron ore and coal).

Table 4 Experiment No. The average particle diameter of iron ore (μm) The content of particles with a diameter of 10 μm or less in iron ore A (wt.%) The average particle size of the coal (μm) The duration of the reaction (min) one 37 6 48 9.3 2 17 32 48 8.8 3 3.9 99 48 7.7 four 37 6 fourteen 9.1 5 37 6 2,4 9.0 6 17 32 fourteen 8.4

The results show that a smaller average particle diameter (D50) of iron ore provides a significant reduction in reaction time. Despite an attempt to mold an iron ore compact with an average particle diameter (D50) of less than 4 μm, it was found that such molding is not possible.

Example 2

Compresses are obtained consisting of a mixture of raw material, including iron oxide-containing material, a carbon reducing agent, melting temperature-regulating agents (limestone, dolomite and fluorite) and a binder. The compacts are loaded into a heating furnace and heated in order to subject the iron oxide in the compacts to reduction smelting, resulting in reduced iron agglomerates.

In this case, iron ores having the composition of the components described in Table 1 are used as the oxide-containing material. Coal having the composition of the components described in Table 5 is used as the carbon reducing agent. As regulating the melting temperature of the agents used limestone having a composition of components (composition of the main components) described in table 6; dolomite having the composition of the components (composition of the main components) described in table 7, and fluorite having the composition of the components (composition of the main components) described in table 8. Pressings are obtained from iron ores having different average particle diameters and different particle size distributions (content particles with a given diameter). In particular, flour serving as a binder is mixed with iron ore mixtures having different average particle diameters and different particle size distributions in the ratio described in Table 9. An appropriate amount of water is added to each of the resulting mixtures. The mixture is agglomerated in a pneumatic granulator in the form of raw pellets with a diameter of 19 mm. The obtained raw pellets are loaded into a dryer and heated at 180 ° C for one hour in order to completely remove the adhesive water, thereby providing agglomerates in the form of pellets (spherical dry pellets).

Table 5 The composition of the components of coal (wt.%) Bonded carbon Volatile component Ash Total 79.5 15.97 4,53 one hundred

Table 6 The composition of the components of limestone (wt.%) SiO ₂ Cao Al ₂ O ₃ MgO S 0.14 56.87 <0.01 0.14 <0.001

Table 7 The composition of the components of dolomite (wt.%) SiO ₂ Cao Al ₂ O ₃ MgO S 2.0 35.71 0.27 16.85 <0.001

Table 8 The composition of the components of limestone (wt.%) SiO ₂ Saobsch Al ₂ O ₃ MgO F 3.05 50.39 0.28 <0.01 47.54

Table 9 Sample mix ratio The ratio of the components of the mixture (wt.%) Iron ore Coal Limestone Dolomite Fluorite Binder Total a 75.04 18.0 1.95 3.31 0.8 0.9 one hundred b 71.32 16.83 7.27 2.88 0.8 0.9 one hundred

Dry pellets are loaded into a heating furnace in which carbon material (anthracite with a maximum particle diameter of 2 mm or less) has been placed. Dry pellets are heated at 1450 ° C in nitrogen atmosphere and determine the time (reaction time) required for reductive melting.

Table 10 describes the results obtained together with the average particle diameters of the used components of the raw materials (iron ores, coal, limestone, dolomite and fluorite) and the content of particles with a diameter of 10 μm or less in iron ores (the content of particles with a diameter of 10 μm or less). Table 10 also describes the general properties of dry pellets (for example, apparent density and analytical value of dry pellets) (average of 10 pellets for each experiment). Of the items described in table 10, measurement methods and criteria for the main items are described below.

Sulfur separation

The ratio of the amount of sulfur [S] in the reduced agglomerates to the amount of sulfur (S) in the components of the slag is calculated (by-product slag formed during the formation of the granulated reduced iron ([S] / (S), sulfur distribution). The sulfur distribution is an indicator of the sulfur of the granulated reduced gland.

Performance (performance index)

The productivity when heating dry pellets in order to subject the metal oxide to smelting to reduced iron agglomerates is calculated by the number (tons) of reduced iron agglomerates obtained per unit time (hours) per area (m ² ) of hearth, according to the following expression (1) :

Productivity (tons / m ² / h) = productivity of granular reduced iron (tons / h) / area (m ² ) of hearth (1)

In the expression (1), the productivity of the granulated reduced iron (tons / hour) is represented by the following expression (2):

Productivity of granular reduced iron (granular reduced iron, tons / hour) = number of loaded compacts (dry pellets) (tons / hour of compacts) × mass of granular reduced iron produced per ton of compacts (tons of granular reduced iron / ton of compacts) × degree of product recovery ( 2)

In expression (2), the degree of product recovery is calculated based on the ratio of the mass of granular reduced iron with a diameter of 3.35 mm or more relative to the total amount of granulated reduced iron obtained [(granular iron with a diameter of 3.35 mm or more (wt.%) / Total weight of granular reduced iron (%) × 100 (%)] (expressed as “yield of granular iron with a diameter of 3.35 mm or more (%)” in Table 10). In Table 10, to quantify the effectiveness of the present invention, compacts (c Chi pellets) in experiment 7, called "comparative compacts"; comparative performance using compacts is 1.00 and productivity is the use of such agglomerates is expressed as a relative value (Performance Index).

Table 10 Experiment No. 7 8 9 10 eleven 12 Type of iron ore BUT BUT BUT BUT BUT AT The average particle diameter (D50) of raw materials
Iron Ore (μm)
Coal (μm)
Limestone (μm)
Dolomite (μm)
Fluorite (μm) 37
21
eleven
56
25 17
eleven
four
3.0
5 17
21
eleven
56
25 four
21
eleven
56
25 37
eleven
eleven
56
25 23
eleven
eleven
56
25 The content of particles with a diameter of 10 μm or less in iron ore (wt.%) 6 32 32 99 6 eighteen A mixture of raw materials a a but but but b Dry pellets
Apparent Density (g / cm ³ ) 2,200 2,273 2,272 2,257 2,209 2,281 The duration of the reaction (min) 10.42 9.44 10.40 9.16 10.64 9.57 Analytical value of dry pellets
Total Iron (%) 50.31 50.29 50.29 50.29 50.41 48.35 Granular Reduced Iron
The output of granular iron with particles with a diameter of 3.35 mm or more (%) 82.47 99.51 100.66 102,44 82.08 103.3 The analytical value of granular reduced iron
S (%) 0,066 0.051 0,050 0,041 0,067 0,022 The analytical value of the slag
S (%) 1,04 1.01 1,02 0.99 1,03 0.84 Sulfur distribution (-)
Performance Index (-) 15.8
1.00 19.8
1.38 20,4
1.26 24.0
1.45 15.4
0.98 38.18
1.36

The results show that if the average particle diameter (D50) of iron ore is 23 μm or less and if it contains particles with a diameter of 10 μm or less in an amount of 18 wt. % or more, the yield of granular reduced iron increases, thereby significantly increasing productivity. The results also show that the amount of sulfur in the granular reduced iron is reduced. Also in example 2, despite the attempt to form a compact from iron ore, the average particle diameter (D50) of which is less than 4 μm, it was found that such formation is impossible.

Example 3

Dry presses with a double structure are obtained from mixtures, each of which includes an iron oxide-containing material having the same composition of components as in Example 2 (type of iron ore: A), a carbon reducing agent, melting temperature-regulating agents (limestone, dolomite and fluorite) and a binder (as for the ratio of the components of the mixture, use the same sample of the ratio of components as the sample described in table 9). In particular, flour serving as a binder is mixed with a mixture containing iron ore, the average particle diameter of which is described in the “Central part” section of table 11. An appropriate amount of water is added to the resulting mixture. The mixture is agglomerated in the form of spherical pellets with a diameter of 9.5 mm in a pneumatic granulator. The obtained pellets are used as nuclei. A mixture containing a feed component with a different average particle diameter is formed concentrically around each core (peripheral parts) in the form of raw pellets with a diameter of 19.0 mm (the content of the mixture in the central part is about 12 wt.% Relative to the entire pellet). The obtained crude pellets are loaded into a dryer and heated at 180 ° C for one hour in order to completely remove the adhesive water, thereby providing agglomerates in the form of pellets (pellets with a double structure).

Pellets with a double structure are loaded into a heating furnace in which carbon material has been placed (anthracite with a maximum particle diameter of 2 mm or less). Pellets with a double structure are heated at 1450 ° C in a nitrogen atmosphere and the degree of reduction (reaction time) is determined in the same manner as in Example 2. Table 11 describes the results obtained together with the average particle diameters (D50) of the raw materials used (iron ore , coal, limestone, dolomite and fluorite). Table 11 also describes the items included in example 2 (in the same evaluative ways as in example 2).

Table 11 Experiment No. 13 Location central part Peripheral part Type of iron ore BUT BUT The average diameter (D50) of the particles of raw materials
Iron Ore (μm)
Coal (μm)
Limestone (μm)
Dolomite (μm)
Fluorite (μm) 17
21
eleven
56
25 37
21
eleven
56
25 A mixture of raw materials but but Dry pellets
Apparent density (g / ^cm3) 2,265 The duration of the reaction (min) 11,4 Analytical value of dry pellets
Total Iron (%) 50.61 Granular Reduced Iron
The output of granular iron with particles with a diameter of 3.35 mm or more (%) 89.45 The analytical value of granular reduced iron
S (%) 0.06 The analytical value of the slag
S (%) 1.06 Sulfur distribution (-)
Performance Index (-) 17.7
1,03

The results obtained show that even when the central part is separately formed from fine particles without the use of fine particles throughout the pellet, an action to improve the yield of granular reduced iron can be achieved, while the separation of sulfur is also improved. As described above, the results show that in the case where only the central part is separately formed from fine particles, even in the case of using fewer small particles of the raw material component, the effect of the present invention can be achieved.

Industrial applicability

The present invention relates to a method for producing reduced iron agglomerates, which comprises loading compacts, which include iron oxide material and a carbon reducing agent, under a movable bed heating furnace, and heating compacts to reduce iron oxide in compacts. The use of compacts, including iron oxide-containing material, the average particle diameter of which is from 4 to 23 microns, and which contains particles, the diameter of which is 10 microns or less, in an amount of 18 wt. % or more, improves the yield of reduced iron agglomerates having a large grain size, shortens production time, which provides increased productivity, and minimizes the content of impurity elements, such as sulfur, in reduced iron agglomerates.

Claims (6)

1. The method of producing reduced iron agglomerates, including:
loading the compacts, which include the iron oxide-containing material and the carbon reducing agent, on under the movable bed heating furnace, and heating the compacts to reduce the iron oxide in the compacts,
they use compacts, each of which includes iron oxide-containing material, the average particle diameter of which is from 4 to 23 microns, and contains particles whose diameter is 10 microns or less, in an amount of 18 wt.% or more. 2. The method of claim 1, wherein the iron oxide-containing material is iron ore. 3. The method according to p. 1 or 2, in which the average particle diameter containing iron oxide material located in the Central part of each of the compacts, is from 4 to 23 microns. 4. A method for producing reduced iron agglomerates, including:
loading the compacts, which include an iron oxide-containing material, a carbon reducing agent and a melting temperature regulating agent, under a movable bed heating furnace, heating the compacts to reduce the iron oxide in the compacts, further heating the compacts in order to at least partially melt the compacts, and coalescence of the iron component,
while using compacts, each of which includes
containing iron oxide material, the average particle diameter of which is from 4 to 23 microns, and contains particles, the diameter of which is 10 microns or less, in an amount of 18 wt.% more. 5. The method of claim 4, wherein the iron oxide-containing material is iron ore. 6. The method according to p. 4 or 5, in which the average particle diameter containing iron oxide material located in the Central part of each of the compacts, is from 4 to 23 microns.